(1) Q = 50 - 6.25P When demand increases by 20%, the new demand Q2 = 1.2 x Q So: 1.2 x Q = 1.2 x (50 - 6.25P) or, Q1 = 60 - 7.5P (2) Original Qd = 50 - 6.25P Qs = - 10 + 12.5P In equilibrium, Qd = Qs 50 - 6.25P = - 10 + 12.5P 18.75P = 60 P = 3.20 Q = - 10 + (12.5 x 3.2) = 30 (3) New Qd = 60 - 7.5P Equating with Qs: 60 - 7.5P = - 10 + 12.5P 20P = 70 P = 3.50, Q = - 10 + (12.5 x 3.5) = 33.75 (4) (a) elasticity of demand = Change in quantity demanded / change in price = 0.20 / [(3.5 - 3.2) / 3.2] ** = 2.13 ** change in quantity demanded = 20% (0.20) given (b) Elasticity of supply = change in quantity supplied / change in price = [(33.75 - 30) / 30] / [(3.5 - 3.2) / 3.2] = 0.125 / 0.0938 = 1.33 Solution (1) Q = 50 - 6.25P When demand increases by 20%, the new demand Q2 = 1.2 x Q So: 1.2 x Q = 1.2 x (50 - 6.25P) or, Q1 = 60 - 7.5P (2) Original Qd = 50 - 6.25P Qs = - 10 + 12.5P In equilibrium, Qd = Qs 50 - 6.25P = - 10 + 12.5P 18.75P = 60 P = 3.20 Q = - 10 + (12.5 x 3.2) = 30 (3) New Qd = 60 - 7.5P Equating with Qs: 60 - 7.5P = - 10 + 12.5P 20P = 70 P = 3.50, Q = - 10 + (12.5 x 3.5) = 33.75 (4) (a) elasticity of demand = Change in quantity demanded / change in price = 0.20 / [(3.5 - 3.2) / 3.2] ** = 2.13 ** change in quantity demanded = 20% (0.20) given (b) Elasticity of supply = change in quantity supplied / change in price = [(33.75 - 30) / 30] / [(3.5 - 3.2) / 3.2] = 0.125 / 0.0938 = 1.33.